When comparing vehicles of the same type, the fuel consumption may be different depending on how each vehicle is driven. In other words, the gas mileage may vary depending on how each vehicle is driven. In commercial vehicles, the fuel consumption directly affects the delivery costs, and therefore, in order to reduce the delivery costs, it is necessary to drive in a fuel-efficient manner.
Especially with large-size commercial vehicles, such as large-size trucks, the amount of fuel consumption is large, and since such vehicles are usually driven for long distances, a great amount of fuel can be saved depending on how the vehicle is driven. This can contribute significantly to the reduction of delivery costs. Furthermore, for business organizations having a great number of large-size trucks operating on a daily basis, the delivery costs are greatly affected based on whether each driver drives with a high gas mileage or a low gas mileage.
Accordingly, it is especially demanded that the drivers of large-size vehicles drive in a fuel-efficient manner. There are some evaluation techniques in which various kinds of vehicle data items are recorded so as to evaluate the level of fuel efficiency in each driving operation.
FIG. 6 illustrates an example of a conventional fuel-efficient-driving evaluator. In FIG. 6, reference numeral 1 indicates a vehicle, reference numeral 2 indicates a vehicle control center, reference numeral 3 indicates a vehicle-data detector, reference numeral 4 indicates a storage unit, reference numeral 5 indicates an evaluating unit, reference numeral 6 indicates a totalizing unit, and reference numeral 10 indicates a memory card.
When the vehicle 1 is being driven, the vehicle-data detector 3 detects data for every parameter related to the evaluation for fuel-efficient driving (the parameters may include, for example, the speed of the vehicle, the average engine speed during an upshift, an idle time, and the operation of the gas pedal). The detected data is then stored in the storage unit 4. Such data may be, for example, stored in the memory card 10 inserted in an in-vehicle storage device.
When the driving is finished, the memory card 10 is ejected, and the vehicle data stored therein is input to the evaluating unit 5 in the vehicle control center 2. The evaluating unit 5 is preliminarily provided with an evaluation standard (threshold value, etc.) and procedure for each vehicle data item. Based on the evaluation standard and procedure, each vehicle data item is evaluated and given an evaluation score.
Each evaluation score is sent to the totalizing unit 6 where the final score is calculated. Such calculation may appropriately be performed by, for example, determining the total value of the evaluation scores or the average value of the evaluation scores.
Alternatively, instead of being transferred via the memory card 10, the vehicle data may be directly input to the evaluating unit 5 from the vehicle 1 via a communication network.
According to the conventional art described above, the evaluation is performed without taking into consideration the state of each of the traveling conditions, and for this reason, it is problematic in that the evaluation is not always appropriate in view of fuel-efficient driving.
The following is a further detailed description of why such a problem occurs.
In the conventional art, when calculating the final score from the evaluation scores given based on the vehicle data items corresponding to the parameters for the fuel-efficient-driving evaluation, the scores corresponding to the evaluation parameters that are not significantly related to the fuel-efficient driving and the scores corresponding to the evaluation parameters that are significantly related to the fuel-efficient driving are equally treated to determine the final score (for example, the scores are simply added). For this reason, even when a vehicle is driven in a manner such that the scores corresponding to the evaluation parameters not significantly related to the fuel-efficient driving are high, the final score still becomes high, meaning that the evaluation is not appropriate in view of fuel-efficient driving.
For example, it is assumed that, in a total driving period, 10% of the period is spent idling, 30% is spent driving on open roads, and 60% is spent driving on highways. In such a case, with the conventional approach, the evaluation scores corresponding to the evaluation parameters, such as the idle time, the speed of the vehicle, the average engine speed during an upshift, and the operation of the gas pedal, are given regardless of the percentage of the time spent for each of the traveling conditions. With all of the evaluation scores being treated equally, the final score is calculated.
This means that the evaluation score of the idle time occupying only 10% of the total driving period is treated the same as the evaluation score of the operation of the gas pedal which occupies 60% of the total driving period and which significantly affects the fuel consumption during driving on highways. Accordingly, even if the percentages of the idle time, the open-road driving time, and the highway driving time in the total driving period are different, the evaluation is performed on an equal basis, and is therefore, not appropriate.
On the other hand, the order of the different traveling conditions, such as highway driving, open-road driving, and idling, may be different every trip and may change depending on, for example, the route taken, the weather, the day of the week, or the traffic condition. Consequently, it is not appropriate to change the setting of the evaluation standards and procedures before each trip.